demo_operator_04_c.cpp

对于一个初涉VC＋＋的人来书

//************************************************
// 重载单目自增"++"运算符
//************************************************

# include <iostream.h>

class Time
{
public:
	Time(){minute=0;sec=0;}
    Time(int m,int s):minute(m),sec(s){}
    Time operator++();    //前置单目运算符重载
    Time operator++(int); //后置单目运算符重载
    void display(){cout<<minute<<":"<<sec<<endl;}
private:
    int minute;
    int sec;
}; 

Time Time::operator++() //前置单目运算符重载函数
{
	if(++sec>=60)
	{
		sec-=60;
		++minute;
	}

	return *this;
}

Time Time::operator++(int) //后置单目运算符重载
{
	Time temp(*this);

	sec++;
	if(sec>=60)
	{
		sec-=60;
		++minute;
	}

	return temp;
}
   
int main()
{
	Time time1(34,59),time2;

	cout<<" time1 : ";
	time1.display();

	++time1;
	cout<<"++time1: ";
	time1.display();

	time2=time1++;
	cout<<"time1++: ";
	time1.display();
	cout<<" time2 : ";
	time2.display();

	return 0;
}